This invention relates to poly(oxyalkylene)-polyester-poly(sulfide)-polythiols. Poly(oxyalkylene)-polyester-poly(sulfide)-polythiols are broadly known as shown by U.S. Pat. No. 3,817,936. These materials are quite useful in applications such as sealants. The compositions are normally liquid and can be easily cured with conventional curing agents such as sulfur to give a weather resistant flexible cured sealant. However, the production of such sealants is rather difficult requiring corrosion-resistant equipment such as glass-lined reactors and the resulting product requires stabilization to avoid gelling on storage.